Spur Gear Calculator — Module, Pitch, Center Distance

System

Module (m)

mm — standard: 1, 1.25, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 10

Diametral Pitch (DP)

teeth per inch — standard: 4, 6, 8, 10, 12, 16, 20, 24

Pressure angle (φ)

Pinion teeth (Z₁)

Gear teeth (Z₂)

Face width (b)

mm — typically 8–12 × module

Center distance

—

mm — m × (Z₁ + Z₂) / 2

Pinion (Z₁)

Pitch diameter (d₁)—

Outside diameter (da₁)—

Root diameter (df₁)—

Base diameter (db₁)—

Gear (Z₂)

Pitch diameter (d₂)—

Outside diameter (da₂)—

Root diameter (df₂)—

Base diameter (db₂)—

Common dimensions

Addendum (ha)—

Dedendum (hf)—

Whole depth (h)—

Circular pitch (p)—

Tooth thickness (s)—

Gear ratio (i)—

Spur Gear Calculator.